The invention relates to new 10-brominated N.sub.b -quaternary derivatives of sandwicine and isosandwicine, process and intermediate materials for their preparation and pharmaceutical compositions and methods of treatment using same.
Sandwicine is an indole alkaloid from the group of rauwolfia alkaloids. This alkaloid is described in detail by M. Gorman et al, Tetrahedron 1, 328 (1957). It is an isomer of the rauwolfia alkaloid ajmaline. Quaternary salts of ajmaline are known to possess valuable pharmacological properties, in particular, antiarrhythmic properties.
From German Pat. Nos. 11 54 120, 11 96 207 and 16 20 559, N.sub.b -quaternary derivatives of ajmaline and isoajmaline are known which exhibit valuable pharmacological activities in particular antiarrhythmic activity. A well known representative of these known quaternary ajmaline derivatives is N.sub.b -propyl ajmalinium hydrogen tartrate which is the active ingredient of an antiarrhythmic pharmaceutical composition which is commercially availble under the tradename Neo Gilurytmal, and is used in the treatment of disorders of the coronary and circulatory system.
It is known that quaternary ajmaline derivatives in addition to their desirable pharmacological properties also possess some undesirable side effects, e.g. negative inotropic properties.
From German Offenlegungsschrift No. 26 11 162, N.sub.b -quaternary derivatives of sandwicine and isosandwicine are known which possess antiarrhythmic properties.